Ultrasonic measurements in sinter-forged high T/sub c/ superconductor YBa/sub 2/Cu/sub 3/O/sub 7- delta /

Both ultrasonic attenuation and velocity as a function of temperature from 4.2 K to room temperature were measured on sinter-forged samples of YBa/sub 2/Cu/sub 3/O/sub 7- delta /, which have more than 80% alignment of the c-axis of the grains parallel to the forging axis. Strong anisotropy was found both in the attenuation and the velocity when propagating sound waves in different directions relative to the forging axis. Hysteresis was observed in the velocity changes.<
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